Plumb bob having vertical light-ray projector



Aug., l, 1950 R. R. EsHl-:R

PLUME B0B HAVING VERTICAL LIGHT-RAY PROJECTOR Filed .July 5o, 1947 2Sheets-Sheet l Aug. l, 1950 R. R. ESHER 2,517,295

PLUMB BOB HAVING VERTICAL LIGHT-RAY PROJECTOR Filed July 30, 1947 2Sheets-Sheet 2 @M nw? 7M Patented Aug. 1, 1950 PLUME BOB HAVING VERTICALLIGHT-RAY PROJECTORl Raymond Robert Esher, Collingdala Application July30, 1947, Serial No. 764,613

45 Claims.

This invention relates to improvements in plumb bobs, especially forindicating a point on the ceiling or other elevated portion of a room indirect alignment with a designated point on the floor or other lowerportion of the room. It is applicable particularly in indicating a pointon the ceiling directly over a corresponding point on the licor.

In laying out and installing uorescent lights or other types of lightingfixtures, it has been diiiicult heretofore to locate the fixtures at thedesired point on the ceiling, with respect to a particular point on thefloor. The only means available heretofore for doing this has been theuse of a plumb bob suspended by a string, but this is very tiresomebecause of the necessity for holding the string' by hand, which makes itnecessary to suspend it for several minutes while the plumb bob stopsswaying. Moreover, it is diflicult to use in some locations, especiallyin open buildings, where the wind would interfere with the use of theplumb bob.

The object of this invention is to improve the construction of plumbbobs, to enable theseto be used in any desired place, withoutdiiiiculty, and without the strain and labor ordinarily involvedheretofore in obtaining a particular location for a fixture.

This object is accomplished, according to a preferred embodiment of theinvention, by utilizing a beam of light suspended from a lamp supportedloosely in a. universal joint so as to act as a plumb bob and to projectthe beam of light to a desired point. This enables the user to obtainthe location quickly and without the labor and diculty of suspending aplumb bob on a string, This is particularly applicable when locating orlaying out a lighting Xture in a set position with respect to the iioor.It can be used also to level conduit risers and switchboards, sliderails on elevator shafts, and other objects that must be plumb.

According to this embodiment of the invention, by way of example, aweighted member is attached to a projecting tube that encloses anelectric lamp for projecting a beam of light through the tube. The tubeis suspended on a universal joint7 so as to be centered automaticallyinan upright position which is absolutely vertical,`with the lightprojecting upwardly, so as to indicate a point on the ceiling or upperportion of the structure directly over and in vertical alignment withthe corresponding point on the floor.

This embodiment is illustrated in the accompanying drawings, in which:

Fig. l. is a side elevation of the plumb bob as an embodiment of theinvention;

Fig. 2 is a similar view at right angles thereto;

Fig. 3 is a vertical sectional view therethrough on the line 3--3 ofFig.,2; l

Fig. 4 is a horizontal sectional view on the line 4-4 of Fig. l;

Fig. 5 is a similar View Fig. l;

Fig. 6 is a detached perspective View of the lens tube; N l

Fig. 7 is a similar view of the lamp support; and

Fig. 8 is a vertical sectional View through the lower portion of thelamp device showing a modification therein. In `the form illustrated inthe drawings, a plumb bob structure includes aibase designated generallyby the numeral l, substantially U-shaped, as shown in Fig. 5, withlateral arms adapted to embrace the `selected point on the licor.`Upstanding from the base l, is a standard 2, for supporting theoperating parts of the plumb bob. The lower end `of the standard 2 isXed to the base i, while the upper end thereof forms a support for theoperating parts.

As shown in Figs. 1 `and 4, a yoke 3 extends laterally from the upperend of the standard 2 and issecured rigidly to the standard by a screw4, which extendsthrough the standard and into a side of the yoke 3, thatis inabutting relation against a side of the standard, forming a clampedconnection between the yoke and the standard.

The-opposite arms `of the yoke 3 carry pointed pins 5 in opposedrelation to each other, each of which `pins is threaded through an armof the `yoke for adjustment relative thereto, and has a lock nutthereon. The pins 5 engage a support and mounting ring l ondiametrically opposite sides of said ring for1freedom of swingingmovement ofthe ring relative to the yoke 3. Similar `pivot pins areshown at 8, to those desigria-ted` 5, `as described, but are `arrangedat right angles to the pins 5 and coacting therewith and with themounting ring 'l to form a universal joint. i

Suspended by the universal joint isa lamp device carried directly on thepins 8, engaging the lamp device at opposite sides for freedom ofswinging movement relative to the pins 81, while the `latter and ring 1are also `free to swingen the pointed pins 5; This assures the locationof the lamp device in an absolutely vertical position by the action ofgravitythereon.

In the form illustrated as an embodiment of on the line 5-5 of 'lamp"casing,

lwill be evident from the drawings, vweighted bob is notrequired forthis purpose howeven but mercury or other Weighing means -may becontained in the housing-section I9, as indicated at 28 in Fig.Spin-which event the lamp Q u the invention, the lamp device includes amounting tube 9, and a lens tube I9, shown as telescoped with respect toeach other for relative vertical adjustment by a pin II, engaging in aslot I2 in the tube I9, the pin il being shown as a screw attached tothe tube 9. This screw may be used to lock the tubes in set positionswith respect to each other, if desired. The tube 9 is engagedat-opposite sides by bearings therein with the pins 8.

A lens is shown at I3 at the upper end of the tube 9, and an additionallens is shown at I4 at the lower end of the tube |0, the lens I4 beingmounted in a lens holder E5, detachably secured by a set screw I6 to thelower end of the tube I9. An additional lens is shown at I1, below thelens I4, although the number and character of these lenses may be variedas desired, according to the desired qualities of the beam of light tobe pro- .lected A lamp housing is shown as formed by sections I8 and I9,telescoped with each other and detachably secured to each other, 4as byscrew threading, friction, or other suitablemanner. A lamp socket 29 ismounted in the housing I8-I9,

lwith a reector `2I extending outwardly therefrom and adapted fordetachable connection of an eleotricflight bulb 22, Withthe socket 29.The socket 29 is shown as mounted by means of a 'spring'ba'il"23,attached to the reflector 2| and frictionally engaging the inner wall ofthe housing I8.

While any desired provision may be made for `energizing 'thelamp22,either from batteries, house current, etc., I have shown-as an example,

the connection of the socket 2] through a wire V'f'ffilttobatteries'25mounted in a holder 26 on the vstandard'Z, vas means for electricallyenergizing the lamp. One side of the batteries may be grounded to theAbase I, as shown, while the opposite side of the lamp will be groundedto the Any suitable provision may be made in the wire 24, forcontrolling the energizing ofthe lamp, as by switch means or the like.

The' lower end of the lamp structure preferably should be weighted so asto hold the tubes S-Ifl 'in a yvertical'position, as well as to act as-a `pointer f for the device.

A weighted bob is shown at 21, in Figs'l and 2, attached to the lowerend of the lamp housing section I9; in position to be located in closekproximity to the 'door or other` support upon which the structure maybe supported, Vas 'A separate housing, preferably, is pointed at itslower lend `as indicated at 29.

The use of the devices will be evident from the foregoing description.When it is desired to 'dctermine a point onthevceiling of aroom, as anexampleywith respect to a particularflocation on the iioor, it isnecessary merelyto set the instrument on the-'iioor with the bob 21,or'the pointed end 29 of the lamp structure, directly over the "desiredpoint. rvThe universal mounting 5-8 al- -lowsthe lampdevice to hang in`-a verticalA position, whereupon the energizing of the lamp 22 `willproject a beam of light vertically to a vpoint on the ceiling Vdirectlyover thenset point on the L floor beneath the pointed'bob'Z'l or 29. Theaction of'vgravity'issufcient to enable the device to assume a verticalposition corresponding in action with'that ofa vpluii'lbloobSuspende'dn.

lto

a string, but without the labor and difficulty normally encountered inholding such a plumb bob. Moreover, the set position may be determinedmuch quicker and more easily than has been possible heretofore With astring supported plumb bob, as well as permitting the use of thisinstrument in many locations where an ordinary plumb bob could not beused.

The instrument can be used also as a surveyors instrument by placing iton a stand with a level attached to one side to indicate the levelposition of the instrument when the light beam will indicate the desiredreading.

`While the invention has been illustrated and described in certainembodiments, it is recognized that variations and changes may be madetherein, without departing from the invention, except as specified inthe claims.

I claim:

l. As a means for selectively indicating overhead'service locations,wherein such location is `remote from the indicating source and requiresunrestricted access thereto to permit unrestrained service activities atthe overhead location point,

portable assemblage adapted to be selectively 'positioned on asupporting surface located below Aand remote from the service locationand to direct a true vertical light-ray beam to said overhead locationto spot-light the'point of service application, said assemblagecomprising a portable support including a vertical standard, a light-rayprojecting instrumentality carried by and suspended within an upper Zoneof the standard with the point of suspension above the mid zone of theinstrumentality, said instrumentality including the light ray projectingmeans and having a .weighted lower end zone swingingly movablerelativeto .the portablesupport and operative to con- .trol the position.and direction of the instrumen- .tality axis, said lower end. Zonebeing pointed with the point approaching the lower plane of the`portable support, the point and the light-ray beam both extending onand being located in ythe instrumentality axis to thereby permitlocation of the assemblage on and positioning of the freely swingablepointedv end in the vicinity of the supporting surface to thereby permitselec- .tive positioning of suchpointed end relative to a predeterminedselected point on the supporting surface vwith the projected beamextending in true'vertical alinement with the selected point and therebyenable the beam to transfer the position of the selected point locationto the overhead location and thereby indicate the point of serviceapplication.

`2. An assemblage as in claim l characterized in 'that the supportincludes an open-ended 'forked base member having its forks positionedto permit free swinging movements of the pointed end within and betweenthe forks of the base member, said base member carrying such verticalstandard in rear of the forks, said v-standard carrying a gimbalmounting for supporting the instrumentality within the upper zone of theinstrumentality and with the girnbal mounting active to permit freeswinging of the Ainstrumentality pivotally with the swinging movementsof the universal type to thereby per- ,mit support accommodation to theconditions of the surface on which the support is mounted. 3. fAnassemblage as in claim l characterized that the weighted zone of theinstrumentality is -in the form of a weighted element of conical contourwith its larger dimension uppermost to constitute the elements as ofplumb-bob characteristic with the upper end having means for rigidlysecuring the element to the lower end zone of the instrumentality, saidelement having a pointed free end axially alined with theinstrumentality axis.

4. An assemblage as in claim 1 characterized in that the instrumentalityincludes a tubular portion adjustable as to length and having a lensformation at its upper end, said portion also having a lens assembly atits opposite end adapted to focus light rays through said upper endlens, the instrumentality having a hollow lower zone equipped with alamp assembly located axially and constituting a source of light rays tobe emitted through the several lenses, said lamp assembly including alamp socket carrying a reflector with the latter carrying a spring bailadapted to engage side walls of the hollow lower zone.

5. An assemblage as in claim l characterized in that the instrumentalityincludes a tubular portion adjustable as to length and having a lensformation at its upper end, said portion also having a lens assembly atits opposite end adapted to focus light rays through said upper endlens, the instrumentality having a hollow lower zone equipped with alamp assembly located axially and constituting a source of light rays tobe emitted through the several lenses, said tubular portion being formedof a pair of telescoping sections adjustably connected below thesuspension point.

RAYMOND ROBERT ESI-IER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 287,580 Roach Oct. 80, 1883444,705 Lambdin Jan. 13, 1891 469,050 Weeks, Jr Feb. 16, 1892 1,113,519Wallace Oct. 13, 1914 1,478,282 Hunter Dec. 18, 1923 1,820,082 McLainAug. 25, 1931 1,829,104 Miller Oct. 27, 1931 1,883,655 Eskilson Oct. 18,1932 2,072,286 Wellington Mar. 2, 1937 2,357,542 Pfeil Sept. 5, 1944

